JP2002196390A - Diaphragm switching device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely switch a diaphragm by a solenoid actuated by low electric power. SOLUTION: A diaphragm aperture 57 is formed on a diaphragm plate 36, and the plate 36 is energized by a spring in a direction where the aperture 57 is inserted in a photographing optical axis. The plate 36 is fixed on a diaphragm lever 59, and the abutting part 59c of the lever 59 abuts on the projecting part 37a of a diaphragm switching lever 37. The lever 37 is energized by larger energizing force than in energizing the plate 36 by the spring. a mark 63b is the locking projection of a charge lever, which locks the projection to be locked 37b of the lever 37 at the time of completing shutter charge. After shutter release, the locking is released and the lever 37 is turned. When subject luminance is dark, the coil 39b of the solenoid 39 is energized and a movable iron core 39a is moved upward. A stopper 38 interlocked with the iron core 39a is retreated from the rotational orbit of the lever 37. The lever 37 presses the plate 36 and turns it to a position where the aperture 57 is retreated from the photographing optical axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm switching device used for a film unit with a lens, for example.

[0002]

2. Description of the Related Art A film unit with a lens is known as a simple camera of a single use type in which a photographic film is pre-loaded. In this film unit with a lens, the cost is reduced thoroughly and the structure of the device itself is simplified. For this reason, in a film unit with a lens, a so-called kicking-type shutter device that opens and closes a shutter by kicking a shutter blade having a single configuration spring-biased to a closed position in an opening direction is used. As an exposure adjusting mechanism to be added to a film unit with a lens having such a shutter device, an aperture plate having a small aperture opening is provided separately from the shutter blades, and the aperture plate is moved according to the photometric value. It is being considered to switch the aperture.

This diaphragm plate is movably mounted between a position where the small aperture opening is inserted on the optical path and a position where it is retracted out of the optical path. The diaphragm plate is driven by a solenoid to open the diaphragm. Switching is performed. The solenoid is incorporated so as to operate according to a detected value of the amount of external light started by operating a shutter button. This makes it possible to adjust the exposure with a simple structure.

In general, a push-pull solenoid is often used as a solenoid for driving an aperture plate. In this case, the diaphragm plate and the solenoid have a simple integrated structure, and switching of the diaphragm is performed by the urging force of a spring attached to the diaphragm plate and the suction force of the push-pull solenoid. For example, in order to switch a diaphragm plate, which is spring-biased toward the retracted position, to a position where the small aperture opening is inserted on the optical path, a suction force larger than the spring urging force is required. .

[0005]

However, as a power source battery for a film unit with a lens, generally, an AA battery is used.
Since only one type of dry cell is used, the current value that can be obtained from this is only a small amount, and it is very difficult to obtain a suction force greater than the above-mentioned spring force with the push-pull solenoid operated by this. It is.

Further, when used on a sandy beach, foreign matters such as sand particles enter the inside of the film unit with the lens and enter between the coil of the push-pull solenoid and the movable core, so that the aperture can be switched reliably. In the worst case, the diaphragm plate stops during the movement and covers the optical path, and there is a possibility that appropriate photographing cannot be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an aperture switching device for a camera capable of reliably switching an aperture even with a push-pull solenoid operated with low power.

[0008]

In order to achieve the above object, an aperture switching device for a camera according to the present invention is movable between a small aperture position and a large aperture position, and a spring is moved toward the small aperture position. When the latch at the initial position is released in conjunction with the biased diaphragm plate and the shutter release, the drive spring is biased to move toward the switching position. A diaphragm switching member for moving the diaphragm plate from the small diaphragm position to the large diaphragm position, and one end protruding into the moving path of the diaphragm switching member, which receives the diaphragm switching member at one end and prevents movement to the switching position. A locking member movable between a locking position and a non-locking position for retracting the one end from the movement path of the aperture switching member and allowing the aperture switching member to move to the switching position; Position the member in the locking position A holding spring for holding, a solenoid that is driven when the measured subject brightness is equal to or lower than a predetermined level, moves a locking member to the non-locking position against the bias of the holding spring, and a shutter charge. And a charging mechanism for interlocking and returning the aperture switching member moved from the initial position to the initial position while accumulating the drive spring and locking the same.

According to a second aspect of the present invention, the aperture switching member and the locking member are rotatably provided in planes parallel to each other, and the locking member is located at the locking position. When it is received, a line connecting the rotation center of the locking member and the one end is arranged so as to be substantially orthogonal.

According to a third aspect of the present invention, the locking member is integrated with the movable iron core of the solenoid, and the driving of the solenoid causes the locking member to move straight and move to the non-locking position. ing. Further, as described in claim 4, the aperture switching member is provided so as to rotate from the initial position and move to the switching position, and the moving direction of the movable iron core of the solenoid is adjusted to the rotation surface of the aperture switching member. They are arranged so as to be substantially orthogonal.

[0011]

FIG. 1 is a perspective view showing the external appearance of the front of a lens-fitted film unit 2 embodying the present invention. On the front surface of the unit main body 3, a photographing lens 5, an object-side finder window 6, a strobe light emitting unit 7, a strobe charge switch 8, a Cds 9, and the like are provided. On the upper surface of the unit body 3, a release button 11, a counter window 12 for displaying the number of remaining photographable frames, and a light guide 13 for strobe charging display are formed. Further, on the back side of the unit body 3, a winding knob 14, an eyepiece side finder window, and the like are exposed.

As shown in FIG. 2, the unit body 3 includes a body base 19 into which the exposure device 16 and the strobe device 17 are incorporated, a front cover 20 attached to cover the front and back of the body base 19, and a rear cover. 21. The front cover 20 has an opening for exposing the photographing lens 5, the objective-side finder window 6, the strobe light emitting unit 7, the strobe charge switch 8, and the like. The front cover 20 is provided with a Cds 9 for measuring the subject brightness so as to be exposed from an opening formed on the front surface.

The rear cover 21 covers the rear surface of the main body base 19, and forms a film passage between the rear cover 21 and the main body base 19 from the film roll chamber 23 through the back of the aperture to the cartridge storage chamber 22. The photographic film 24 is stored from the film roll chamber 23 into the film cartridge 25 loaded in the cartridge storage chamber 22 through the film passage. Further, bottom covers 21a and 21b are formed at the bottom of the rear cover 21, and the cartridge storage chamber 22 is formed by these bottom covers 21a and 21b.
And the bottom of the film roll chamber 23 is closed light-tight. The bottom cover 21a of the cartridge storage chamber 22 is openable and closable, and also functions as a take-out cover for taking out a film cartridge 25 containing all the photographed films 24 already taken.

A cartridge chamber 22 and a film roll chamber 23 are integrally formed on the left and right sides of the main body base 19, and an exposure device 16 is provided between them. Further, between the exposure device 16 and the film roll chamber 23,
The strobe device 17 is attached by nail coupling. In the cartridge chamber 22 and the film roll chamber 23, a film cartridge 25 and a film roll 24a, which is a roll of the photographic film 24, are loaded. A winding knob 1 is provided above the cartridge chamber 22.
4 is rotatably disposed, and a shaft member provided integrally therewith is engaged with a spool of a film cartridge 25 stored in the cartridge chamber 22. By rotating the winding knob 14 in the counterclockwise direction in the figure, the photographed photo film 24 is wound into the film cartridge 25.

The strobe device 17 is a unit obtained by assembling a strobe light emitting section 7, a main capacitor 31, a battery 32, a synchro switch 33 and the like on a circuit board 30. When the strobe charging switch 8 is slid upward, the metal contact piece 3 provided on the circuit board 30 is moved.
4 turns ON, and charging of the main capacitor 31 is started. The strobe device 17 includes a pressing piece 35c of the shutter blade 35 which rotates when the shutter mechanism is operated.
(See FIG. 4), the synchro switch 33 is short-circuited and emits strobe light. When the strobe charging switch 8 is slid upward, a part of the light guide 13 projects from the unit body 3.

The exposure device 16 is formed substantially at the center of the main body base 19. The aperture switching device of the present invention is incorporated in the exposure device 16 and includes a shutter mechanism, an aperture plate 36, an aperture switching lever 37, a stopper 38, a push-pull solenoid 39, a Cds9, and a photometric switch 4 described later.
Consists of zero. In addition, a film unwinding mechanism, a counter mechanism for displaying the number of remaining photographable frames, a finder, and the like are incorporated in the exposure device 16, and these are assembled in the dark box 41 to form a unit. A shutter blade 35 and a lens holder 42 are attached to the front surface of the dark box 41 in this order.

As shown in FIG. 3, the shutter blade 35
It is composed of one sector blade, and is rotatably attached to a pin 43 formed in a dark box 41.
Normally, the shutter blades 35 are biased by a spring 44.
The blade portion 35a is held at a closed position for closing the photographing opening 46, and a shutter lever 45 (described later) that operates in conjunction with the pressing of the release button 11 at the time of photographing mounts 35b.
Is kicked off and pivots to an open position (clockwise in the figure) to open the photographing opening 46. Thereafter, the shutter blades 35 return to the closed position by the urging of the springs 44. During the rotation of the shutter blades 35, the shutter opening 46 is opened to perform exposure. The shutter blade 35 has a pressing piece 35c for pressing a synchro switch 33 provided in the flash device 17. Shutter blade 35
Comes to the fully open position where the shutter opening 46 is fully opened,
The pressing piece 35c turns on the synchro switch 33.

The lens holder 42 holds the photographing lens 5 inside the lens barrel 42a, and has an opening 50 serving as a fixed diaphragm formed behind the lens 5. The taking lens 5 is composed of two lenses, a first lens 51 and a second lens 52, and an arc-shaped spacer 54 is arranged between them.
For the first lens 51, a meniscus lens having a convex surface on the object side is used, and for the second lens 52, a biconvex lens is used. A lens cover 53 is attached to the front surface of the lens barrel 42a. The lens cover 53 holds down the outer periphery of the first lens 51, and the photographing lens 5 is held between the lens holder 42 and the lens cover 53. A cutout is provided in a part of the lens barrel 42a and the lens cover 53, and the tip of the diaphragm plate 36 enters the lens barrel 42a from the cutout, and the aperture is switched.

The aperture plate 36 is formed in a substantially L-shape.
An opening 50 formed in the lens holder 42 is provided at the tip thereof.
An aperture 57 having a smaller diameter than that of the aperture 57 is formed. The distal end of the diaphragm plate 36 includes a first lens 51 and a second lens 5.
2, and is held so that the aperture opening 57 is located at the center of the photographing optical axis.

The diaphragm lever 59 includes a shaft member 59a, a mounting portion 59b, and a contact portion 59c. The aperture lever 59 is rotatably attached to a pin 60 formed on the main body base 19. The aperture plate 36 is fixed to the mounting portion 59b. A spring 58 is attached to the diaphragm lever 59, and the diaphragm plate 36 is urged in a clockwise direction in the figure when the diaphragm opening 57 is inserted into the photographing optical axis. Contact part 59c
Protrudes upward from the rear end of the shaft member 59a, and comes into contact with the aperture switching lever 37 described later.

The aperture switching lever 37 is disposed so that its longitudinal direction is orthogonal to the photographing optical axis, and includes a projection 37a that contacts the aperture lever 59 and a locked projection that is locked by a charge lever 63 described later. 37b and a shaft portion 37c are formed. The shaft portion 37c protrudes from the back side of the aperture switching lever 37, and is fitted in a fitting hole 64 formed in the main body base portion 19. The aperture switching lever 37 is urged clockwise in the figure by a spring 65, and the projection 3
7a presses the aperture lever 59. The spring 65 is set to have a larger biasing force than the spring 58 that biases the diaphragm plate 36, and rotates the diaphragm plate 36 counterclockwise in the drawing against the biasing force of the spring 58. The aperture opening 57 is urged in a direction to be retracted from the photographing optical axis.

A stopper 38 is disposed below the distal end of the aperture switching lever 37. The stopper 38 includes a shaft 38a, a protrusion 38b protruding in a direction orthogonal to the central axis of the shaft 38a, and a fitting portion 38c arranged in parallel to the shaft 38a. The fitting portion 38c is rotatably fitted to the movable iron core 39a of the push-pull solenoid 39 disposed behind the stopper 38. The stopper 38 is arranged so as to rotate in a plane parallel to the aperture switching lever 37, and a projection 38c protrudes on a track on which the aperture switching lever 37 rotates. The locking position for receiving 37, and withdrawing from the track,
The aperture switching lever 37 is attached so as to be rotatable between a non-locking position allowing rotation.

When the stopper 38 is at the locking position, the tip of the projection 38c of the stopper 38 is connected to the shaft 38a.
, The distal end of the aperture switching lever 37 is located substantially horizontally from the shaft 37c. In this manner, at a position where the longitudinal direction of the projection 38c of the stopper 38 and the longitudinal direction of the aperture switching lever 37 are substantially orthogonal to each other,
The stopper 38 receives the aperture switching lever 37. In other words, the distal end of the projection 38c receives the distal end of the aperture switching lever 37 in substantially the same direction as the direction in which the aperture switching lever 37 rotates.
8 can surely prevent the rotation of the aperture switching lever 37.

The push-pull solenoid 39 comprises a movable iron core 39a, a coil 39b, a holding frame 39c for holding the coil 39a, and a holding spring 39d. Holding frame 39
c engages with an engaging claw 71 formed on the main body base 19.
The movable iron core 39a is slidably mounted inside the coil 39b, and is urged by a holding spring 39d to be held at a position protruding below the coil 39b. The push-pull solenoid 39 is of a type that generates a magnetic force for attracting the movable iron core 39a by energizing the coil 39b, and energizing this coil is performed via a control circuit by a photometric value of the object luminance by Cds9. Will be Only when the photometric value of the subject luminance by Cds9 is smaller than a predetermined level, the coil 39b
, The movable iron core 39a is drawn into the coil 39b.

When the power supply to the coil 39b is cut off, the movable iron core 39a is connected to the holding spring 3 as described above.
It is held at a position protruding below the coil 39b by the bias of 9d. At this time, the stopper 38 attached to the movable iron core 39a is at a locking position for preventing the rotation of the aperture switching lever 37. The rotation of the aperture switching lever 37 received by the protrusion 38c is stopped by the stopper 38, and the urging by the spring 65 is stopped, and the projection 37a does not press the aperture lever 59. Aperture plate 36, which has been stopped being urged by aperture switch lever 37
Is at a small aperture position where the aperture opening 57 is inserted into the photographing optical axis by the bias of the spring 58.

When the coil 39b is energized, the movable iron core 39a moves upward by the attraction force from the coil 39b against the bias of the holding spring 39d.
At this time, the stopper 38 rotates from the locked position to the unlocked position in conjunction with the movement of the movable iron core 39a. Aperture switching lever 37 whose stopper 38 is retracted and allowed to rotate
Presses the aperture lever 59 by the bias of the spring 65.
Then, the aperture plate 36 urged by the aperture switching lever 37 rotates from the small aperture position described above to a large aperture position where the aperture opening 57 is retracted from the photographing optical axis. Thus, the push-pull solenoid 39 is used as a drive source for rotating the stopper 38.

As shown in FIG. 4, the shutter mechanism is a dark box 4
1 above. This shutter mechanism includes a winding stop lever 72, a shutter lever 45, a delay lever 7
4. It comprises a charge lever 63, a cam 75, and a governor mechanism 76. The cam 75 is provided with a disc 77 and a semi-disc-shaped first cam 78 and a second cam 79 below the disc 77. A notch 77a for locking the locking piece 72a of the winding lever 72 is formed in the disk 77. First
The cam 78 has a hook 4 of the shutter lever 45
5b contacts. The second cam 79 is formed at a predetermined distance from the first cam 78, and a shoulder 74 d of the delay lever 74 abuts the outer periphery of the second cam 79. The cam 75 is inserted into a boss 80 formed in the dark box 41, and the lower end of the shaft portion 75 a is engaged with the engagement hole 82 a of the sprocket 82.
It is arranged to engage with. When the photographed photo film 24 is stored in the cartridge 25, the sprocket 82 engages with the perforations formed on the photo film 24, rotates counterclockwise in the drawing, and
The cam 75 also rotates. At the same time, the counter plate for displaying the remaining number rotates.

The shutter lever 45 is rotatably attached to a pin 84 provided on the dark box 41. The shutter lever 45 includes a kicking arm 45 a for kicking off the tip of the shutter blade 35, a hook 45 b abutting on the first cam 78 of the cam 75, and a projection 45 c locked on the delay lever 74. Further, a torsion spring 85 is provided above the shutter lever 45, and the torsion spring 85 causes the shutter lever 4 to move.
5 is urged counterclockwise in the figure.

The winding lever 72 includes a locking claw 72a, a projection 72b, a release part 72c, and a winding part 72d, and is rotatably attached to a shaft 87 provided in the dark box 41. The winding stop lever 72 has a torsion spring 88.
Is attached and urged clockwise in the figure. The projection 72b of the winding stop lever 72 is arranged so as to abut on the locking piece 74c of the delay lever 74. Locking claw 72a
Is provided to enter the notch 777a of the cam 75. When the winding stop lever 72 rotates clockwise in the drawing, the winding stop 72d engages with a groove formed on the outer peripheral portion of the winding knob 14 to lock the rotation of the winding knob 14. When the release button 11 is pressed, the release portion 72c presses the pressing piece 1 formed below the release button 11.
1a, and rotates counterclockwise in the figure.

The delay lever 74 is rotatably attached to a shaft 86 formed on the upper part of the dark box 41, and constitutes a delay mechanism together with the governor mechanism 76. The delay lever 74 has a gear 74a formed at one end thereof.
The gear 74a meshes with the switch gear 90 of the governor mechanism 76. A pin 74 is located near the gear 74a.
b is formed. The delay lever 74 is urged counterclockwise in the figure by a torsion spring 89 attached to the pin 74b. Also, the delay lever 7
A locking piece 74c is formed on the upper surface of 4. The locking piece 74c locks with the projection 72b of the winding stop lever 72. Further, the shoulder 74 d abuts on the second cam 79 of the cam 75.

The governor mechanism 76 includes a switch gear 90 and an ankle 91, and is disposed above the dark box 41. The rotation speed of the switch gear 90 is
Is adjusted by As described above, the switch gear 90 is engaged with the gear 74a of the delay lever 74, and follows the rotation of the delay lever 74. Therefore, the governor mechanism 76 operates as a speed adjusting mechanism for adjusting the rotation speed of the delay lever 74. As shown in FIG. 5, a fan-shaped pressing rib 9 is provided below the switch gear 90.
0a is formed, and the charge lever 63 pressed by the rotation of the pressing rib 90a rotates clockwise in the drawing. Further, a pin 90b is formed on the upper portion of the switch gear 90, and the rotation of the pin 90b makes contact with the photometric switch 40, and the photometric switch 40 is turned on. The governor mechanism 76 delays kicking of the shutter blades 35 by the shutter lever 45, during which Cds
9 and the switching of the aperture plate 36 is reliably performed.

The charge lever 63 is formed in a substantially L shape, and has an arm 63a and a locking projection 63b formed on the upper surface thereof. A torsion spring 93 is attached to the charge lever 63 and is urged counterclockwise in the figure. The arm 63a protrudes above the charge lever 63, and has an abutting surface 63c at its tip and a pressed portion 63d at its lower end.
Are formed. The contact surface 63c is provided with a switchgear 90.
Are arranged so as to contact the side surfaces of the charging lever 93 by the biasing of the torsion spring 93 as described above.
Is urged in the counterclockwise direction in the figure, but the contact surface 63c comes into contact with the switch gear 90 and the rotation stops. Pressed part 63
d is pressed by the pressing rib 90a of the switch gear 90, and rotates the charge lever 63 clockwise in the figure against the bias of the torsion spring 93. The locking projection 63b is
The locked projection 37b of the aperture switching lever 37 is locked to hold the aperture switching lever 37.

Next, the operation of the present embodiment will be described. FIG.
Shows a shutter mechanism after shutter release. In FIGS. 5, 6, and 7, the ankle 91 of the governor mechanism, various springs, and the like are omitted to prevent the drawings from being complicated. The stop lever 72 is urged clockwise in the figure by a torsion spring 88, but the protrusion 72b and the locking piece 74c of the delay lever 74 abut, so that the stop portion 72d is It is held at an initial position outside the groove 14a formed in the outer peripheral portion. On the other hand, the charge lever 63 is
3, the contact surface 6 is urged in the counterclockwise direction.
3c is in contact with the side surface of the switch gear 90, and its rotation is stopped. At this time, the locking projection 63b of the charge lever 63 is
7b.

When the cam 75 rotates with the winding of the photo film 24, the second cam 79 also presses the shoulder 74d of the delay lever 74 as shown in FIG. As a result, the delay lever 74 starts rotating clockwise. As shown in FIG. 7, when the delay lever 74 rotates a predetermined amount, the engagement between the locking piece 74c of the delay lever 74 and the projection 72b of the locking lever 72 is released, and the locking lever 72 rotates clockwise. Rotate a predetermined amount. When the winding of one frame of the photo film 24 is completed,
The locking claw 72a enters a notch 77a formed in the disk 77 of the cam 75. At the same time, the winding stopper 72d enters the groove 14a formed in the outer peripheral portion of the winding knob 14, and the rotation of the winding knob 14 is prevented. The delay lever 74 attempts to rotate in the counterclockwise direction by the bias of the spring 89. However, the rotation of the delay lever 74 is stopped by the locking of the protrusion 72b of the locking lever 72 and the locking piece 74c. .

On the other hand, when the delay lever 74 rotates clockwise in the figure, the switch gear 90 starts to rotate counterclockwise in the figure following the rotation. When the switch gear 90 rotates by a predetermined amount, the pressing rib 90a presses the pressed portion 63d of the charge lever 63, and rotates the charge lever 63 clockwise in the figure against the bias of the spring 93. And
As shown in FIG. 7, when the shutter is charged, the pressed portion 63d contacts the outer peripheral surface of the pressing rib 90a, and the charge lever 63 is held. As the charge lever 63 rotates against the bias of the spring 93, the biasing force of the spring 93 to rotate the charge lever 63 in the counterclockwise direction in the drawing is accumulated, as shown in FIG. With the shutter charged, a driving force sufficient to rotate the charge lever 63 is accumulated in the spring 93.

Further, while the charge lever 63 is rotating clockwise in the drawing, the locking projection 63b comes into contact with the locked projection 37b of the aperture switching lever 37, and the aperture switching lever 37 is moved to the position shown in FIG. It is gradually rotated to the initial position shown. At this time, the aperture switching lever 37 rotates counterclockwise in the figure against the urging force of the spring 65, so that the spring 65 rotates the aperture switching lever 37 clockwise in the figure. Power is stored. In the shutter charged state, the locking projection 63b of the charge lever 63 locks the locked projection 37b of the aperture switching lever 37, stops the rotation of the aperture switching lever 37, and holds the initial position. ing. Aperture switching lever 3 in this initial position
Reference numeral 7 is located at a position away from the aperture lever 59 as shown in FIG. As a result, since the diaphragm plate 36 is not biased by the diaphragm switching lever 37, it is rotated only by the bias from the spring 58, and the diaphragm opening 57 is moved to the small diaphragm position where the diaphragm opening 57 is inserted into the photographing optical axis. is there. Further, in the initial position, a driving force sufficient for the aperture switching lever 37 to press the aperture lever 59 is accumulated in the spring 65.

When the release button 11 is pressed with the shutter charged, the pressing piece 11a formed below the release button 11 presses the release portion 72c of the stop lever 72. Thereby, the stop lever 72
Rotates counterclockwise in the figure against the bias of the spring 88.
Then, the locking between the locking piece 74c of the delay lever 74 and the projection 72b of the winding stop lever 72 is released. The delay lever 74 rotates counterclockwise by the bias of the spring 89. This rotation causes the switchgear 9 of the governor mechanism 76 to rotate.
1 rotates, the pin 90b and the photometry switch 92 come into contact with each other, and photometry of the subject image by Cds9 is performed. Cds
Based on the photometric value of 9, whether or not the power is supplied to the push-pull solenoid 39 is determined.

When the delay lever 74 rotates counterclockwise, the pressing rib 90a is displaced from the rotation track of the pressed portion 63d of the charge lever 63, and the charge lever 63 rotates counterclockwise in FIG. I do. As a result, the engagement between the locking projection 63b of the charge lever 63 and the locked projection 37b of the aperture switching lever 37 is released, and the driving force stored in the spring 65 causes the aperture switching lever 37 to move clockwise in the drawing. To rotate. At this time, when the measured value of the subject luminance by Cds9 is larger than a predetermined value, the power supply to the push-pull solenoid 39 is cut off, and the stopper 38 is at the locking position. Locking projection 63b
After being slightly locked in the clockwise direction in the figure, the rotation of the aperture switching lever 37, which has been released by the lock, is stopped by the stopper 38, as shown in FIG. The aperture switching lever 37, whose rotation has been prevented by the stopper 38, does not press the aperture lever 59, so that the aperture plate 36 remains at the small aperture position.

When the measured value of the subject luminance is smaller than the predetermined value, the push-pull solenoid 39 is energized, and the stopper 38 is moved from the locked position to the non-locked position as shown in FIG. Rotate. The stop switching lever 37, which has been released from being stopped from being stopped by the stopper 38, rotates toward the switching position, presses the stop lever 59, and moves the stop plate 36 from the small stop position to the large stop as shown in FIG. Rotate to the position.

On the other hand, after the aperture plate 36 has been switched, the end of the delay lever 74 whose rotation speed has been adjusted by the governor mechanism 76 and the projection 73 of the shutter lever 73
The shutter lever 73 is rotated in the counterclockwise direction in the drawing, and the shutter blade 35 is kicked off by the kicking arm 73a. Thus, the exposure to the photographic film 24 is performed in a state where the aperture plate 36 is held at the large aperture position or the small aperture position.

FIG. 12 is a timing chart of the aperture switching device. Since the movement of the aperture plate 36 is taken into consideration, the setting is made when the subject brightness is low. When the release button 11 is pressed down, the stop lever 72 rotates, releasing the delay lever 74 and stopping. Thereafter, the delay lever 74 starts to rotate, and the switch gear 90 starts to rotate accordingly. This timing chart shows the time after the time T1 when the switch gear 90 starts to rotate. When the switch gear 90 is started, first, the photometric switch 40 with which the pin 90b is in contact is turned on at time T2, and the Cds9 starts photometry. Then, at time T3, the charge lever 63 starts rotating, and from time T4 to T5, the push-pull solenoid 39 operates, and the stopper 38 rotates from the locked position to the unlocked position. At this time, since the start of the charge lever 63 is adjusted by the delay lever 74 and the governor mechanism 76, the unlocking of the aperture switching lever 37 starts at time T5 when the stopper 38 is switched. As a result, the aperture plate 36 can be smoothly rotated without being received by the stopper 38 during a period from time T6 to T7 immediately after the release of the lock of the aperture switching lever 37 is started. The aperture can be switched from the position to the large aperture position by a stable operation.

The shutter lever 73 whose start is delayed by the delay lever 74 and the governor mechanism 76
Starts rotating from time T8, and from time T9 to T10, the shutter blade 35 rotates to perform exposure. Thus, the push-pull solenoid 39 is
It is used only for turning. As further mentioned above,
Since the distal end of the projection 38c receives the distal end of the aperture switching lever 37 in substantially the same direction as the direction in which the aperture switching lever 37 rotates, the stopper 38
Even when the urging force by the lever 5 is strong, the aperture switching lever 37
Can be reliably prevented from rotating. When the diaphragm plate 36 moves to the small diaphragm position, the charge lever 63 rotates the diaphragm switching lever 37 to the locking position by the driving force stored in the spring 93, and releases from the pressing of the diaphragm switching lever 37. When the diaphragm plate 36 is rotated by the bias of the spring 58 to rotate to the small diaphragm position, and when the diaphragm plate 36 moves to the large diaphragm position, the diaphragm 65 is driven by the driving force stored in the spring 65. Since the switching lever 37 presses the aperture lever 59 to rotate the aperture plate 36, the movement to the small aperture position and the movement to the large aperture position are not the driving force of the push-pull solenoid 39, but The diaphragm plate 36 is driven only by the urging by the spring. As a result, the push-pull solenoid 39 can be reliably operated with low power, and the diaphragm plate 36 can be switched.

In the above example, when switching from the small aperture position to the large aperture position, the start of the charge lever 63 is adjusted by the delay lever 74 and the governor mechanism 76, so that the stopper 38 is switched. The release of the lock of the aperture switching lever 37 starts at time T5, but the present invention is not limited to this, and the timing at which the charge lever 63 rotates is advanced, for example, before the time T4 at which the stopper 38 switches. Alternatively, release of the lock of the aperture switching lever 37 may be started. in this case,
The unlocked lever switching lever 37 is temporarily received by the projection 38c of the stopper 38 while rotating clockwise in the drawing. When the stopper 38 is switched between the times T4 and T5, the stopper 38 rotates while receiving the urging force from the aperture switching lever 37. Therefore, the push-pull solenoid 39 for driving the stopper 38 is smaller than the above-described example. A slightly larger driving force is required, but with less driving force than a push-pull solenoid that directly switches the conventional diaphragm plate,
The stopper 38 can be switched. Immediately after the stopper 38 is switched to the non-locking position at the time T5, the aperture switching lever 37 starts rotating again, and the aperture plate 3
6 can be switched from the small stop position to the large stop position. Alternatively, the timing at which the charge lever 63 rotates is further delayed than in the above example, and the unlocking of the aperture switching lever 37 is started after the time T5 when the stopper 38 is switched to the unlocked position. Is also good. Thereby, the aperture switching lever 37 and the stopper 38
The diaphragms can be switched with a small driving force without any contact when switching the diaphragms.

In the first embodiment described above, the stop switch 38 is received by the stopper 38 interlocking with the push-pull solenoid 39, and the stop position for stopping the rotation and the stop of the stop switch 37 are turned. It retracts from the moving track and moves between the non-locking position allowing rotation, and switches the aperture position. However, the present invention is not limited to this, and the stopper 38 is omitted, The movable iron core 39 a of the push-pull solenoid 39 may have the same function as the stopper 38. Hereinafter, a second embodiment of the present invention in which the movable iron core 39a has the same function as the stopper 38 will be described. However, the same components and members as those described in the first embodiment will be described. The description is omitted using the same reference numerals.

As shown in FIG. 13, the push-pull solenoid 39 has a direction in which the movable iron core 39a moves straight so that the movable iron core 39a projects on a track on which the aperture switching lever 37 rotates, and The rotation surface is disposed so as to be substantially orthogonal. Thereby, the coil 39
b, the power supply to the movable iron core 39a is stopped.
Is located at a position protruding forward in the drawing, and is at a locking position for receiving the aperture switching lever 37 and preventing rotation. The diaphragm switching lever 37, whose rotation has been prevented by the movable iron core 39a, does not press the diaphragm plate 36, so that the diaphragm plate 3
6 remains at the small aperture position. At this time, the movable iron core 39 receiving the rotation of the aperture switching lever 37
Since a is held around the coil 39b,
The rotation of the aperture switching lever 37 can be reliably prevented.

Further, when the coil 39b is energized, the movable iron core 39a is sucked toward the back side in the drawing, and is moved to the non-locking position where it is retracted from the track on which the aperture switching lever 37 rotates. is there. Then, when the movable iron core 39a is at the non-locking position, as shown in FIG. 14, the aperture plate 36 which is biased by the aperture switching lever 37 rotates from the small aperture position to the large aperture position. Thus, the stopper 38 is attached to the movable iron core 39a of the push-pull solenoid 39.
When the diaphragm plate 36 moves to the small diaphragm position, the charge lever 63 is switched by the driving force stored in the spring 93, similarly to the first embodiment. Rotate the lever 37 to the locking position,
The aperture plate 36 released from the pressing of the aperture switching lever 37 rotates by the bias of the spring 58 and rotates to the small aperture position,
When the diaphragm plate 36 moves to the large diaphragm position, the diaphragm switching lever 37 presses the diaphragm lever 59 to rotate the diaphragm plate 36 by the driving force stored in the spring 65. In both of the movement and the movement to the large aperture position, the aperture plate 36 is driven not by the driving force of the push-pull solenoid 39 but only by the urging by the spring. As a result, the push-pull solenoid 39 can be reliably operated with low power, and the diaphragm plate 36 can be switched.

In the first and second embodiments, a small aperture opening having a smaller diameter than the aperture opening formed in the lens holder is provided on the aperture plate, and the small aperture opening is inserted into the photographing optical path. 1 and a second position in which the small aperture opening is retracted from the imaging optical path. The aperture plate is provided with two large and small aperture openings, and the small aperture opening is inserted in the imaging optical path. It is also possible to adopt a method of switching between a first position at which a large aperture opening is inserted on the photographing optical path and a second position at which a large aperture opening is inserted on the photographing optical path.

In the above example, the present invention has been described as an example in which the present invention is applied to a film unit with a lens. However, the present invention may be applied to a compact camera or the like. Further, although the IX240 type cartridge has been described as the photo film, other types may be used. For example, a 135 type cartridge may be used.

[0049]

As described above in detail, the aperture switching device for a camera according to the present invention is movable between a small aperture position and a large aperture position, and is spring-biased toward the small aperture position. The diaphragm plate and the shutter plate are moved toward the switching position by the bias of the driving spring stored when the lock at the initial position is released in conjunction with the shutter release, and the diaphragm plate is moved by moving to the switching position. An aperture switching member for moving from the small aperture position to the large aperture position, and a locking position for projecting one end into the movement path of the aperture switching member, receiving the aperture switching member at this one end, and preventing movement to the switching position. A locking member that retracts the one end from the movement path of the aperture switching member, and is movable between a non-locking position that allows the aperture switching member to move to the switching position; Holding bar to hold in stop position And a solenoid that is driven when the measured subject brightness is equal to or lower than a predetermined level, moves a locking member to the non-locking position against the bias of the holding spring, and interlocks with a shutter charge to initialize the solenoid. And a charge mechanism for returning and locking the aperture switching member moved from the position to the initial position while accumulating the drive spring.
With a push-pull solenoid that operates with low power, the aperture can be switched reliably.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a film unit with a lens.

FIG. 2 is an exploded perspective view of the film unit with a lens.

FIG. 3 is an exploded perspective view of the exposure apparatus.

FIG. 4 is an exploded perspective view of a shutter mechanism.

FIG. 5 is a schematic view showing a main part of a shutter mechanism, showing a state immediately after a shutter release.

FIG. 6 is a schematic view showing a main part of a shutter mechanism, showing a state where only a shutter lever is charged.

FIG. 7 is a schematic diagram showing a main part of the shutter mechanism, showing a state where a delay lever and a charge lever are charged.

FIG. 8 is a schematic diagram showing a main part of the aperture switching device, showing a state in which a charge lever is charged.

9 shows a state where the subject is bright after the state of FIG.

FIG. 10 shows a state where the subject is dark after the state of FIG.

FIG. 11 shows a state where exposure is performed on the photographic film after the state of FIG. 10;

FIG. 12 shows a timing chart of the aperture switching device.

FIG. 13 is a schematic diagram showing a main part of an aperture switching device according to another embodiment different from that shown in FIG. 8;

FIG. 14 shows a state where the subject is dark after the state of FIG. 13;

[Explanation of symbols]

 2 Film unit with lens 5 Photographing lens 9 Cds 11 Shutter button 16 Exposure device 35 Shutter blade 36 Aperture plate 37 Aperture switching lever 37b Locked projection 38 Stopper 39 Push-pull solenoid 40 Photometry switch 41 Dark box 42 Lens holder 59 Aperture lever 63 Charge Lever 63b Locking projection 63d Pressed portion 72 Locking lever 73 Shutter lever 74 Delay lever 75 Cam 82 Sprocket 90 Switch gear 90a Press rib 90b Pin

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 17/00 G03B 17/00 D G03C 3/00 G03C 3/00 Z C

Claims (4)

[Claims] 1. An aperture plate which is movable between a small aperture position and a large aperture position, is urged by a spring toward the small aperture position, and is released from an initial position in conjunction with a shutter release. A diaphragm switching member that moves toward the switching position by the bias of the driving spring stored when the diaphragm is moved, and moves the diaphragm plate from the small diaphragm position to the large diaphragm position by moving to the switching position; and a diaphragm switching member. One end protrudes into the movement path of the aperture stop, and receives the aperture switching member at this end to prevent movement to the switching position. A locking member that is movable between a non-locking position that allows movement to the switching position, a holding spring that holds the locking member at the locking position, and a measured subject brightness that is equal to or lower than a predetermined level. Drive when A solenoid for moving the locking member to the non-locking position against the bias of the holding spring; and interlocking with the shutter charge, the diaphragm switching member moved from the initial position while accumulating the driving spring. An aperture switching device for a camera, comprising: a charging mechanism that is returned to an initial position and locked. 2. The stop switch member and the stop member are rotatably provided in planes parallel to each other, and when the stop member receives the stop switch member at the stop position, the stop member rotates. 2. A device according to claim 1, wherein a line connecting the center and said one end is substantially orthogonal. 3. The locking member is integrated with a movable iron core of a solenoid, and driven by the solenoid, the locking member moves straight and moves to a non-locking position.
An aperture switching device for a camera according to the above. 4. A diaphragm switching member is provided so as to rotate from an initial position to move to a switching position, and a moving direction of a movable iron core of a solenoid is substantially orthogonal to a rotation surface of the diaphragm switching member. The aperture switching device for a camera according to claim 3.